As development of information and communication industry has advanced, high-performance display devices have been demanded. For example, an organic EL (ElectroLuminescence) element is a self-light-emitting-type display device, which is excellent in terms of viewing angle, contrast, and response speed (for example, Patent Literature 1).
Such a self-light-emitting-type element such as an organic EL device includes a first electrode, a functional layer including a light emitting layer, and a second electrode in this order on a substrate, and elements next to each other are separated from each other by an insulating layer (a pixel separation layer).